Anyone know of any good apps to password protect folders/files

Unfortunately there are times when i need to share my desktop with people at work.
I don't necessarily need the files to be "hidden"....just unopenable without password. these files are primarily excel files with employee records/sensitive business records (nothing life or death, just would rather keep prying eyes away)
If it makes it easier, i could throw all of these files in a single folder and just password protect the folder.

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